1. Field of the Invention
The present invention relates to a roller type linear guideway, linear guideway is widely used on machinery trade, automatic equipments, measuring machines, electronic instruments, and the likes. However, the roller type linear guideway is used on large machine.
2. Description of the Prior Arts
Linear guideway generally comprises a rail, a slide block mounted on the rail, and a plurality of rolling elements disposed between the slide block and the rail. If the rolling elements are cylindrical rollers, the guideway is called roller type linear guideway.
A rolling-element-circulating system of the roller type linear guideway generally comprises the rolling-element-retainer, the return path, the return unit, and etc. the circulating system of the roller type linear guideway is generally made up of a plurality of independent components or integrally formed by plastic ejection.
JP Patent 2002-54633 discloses a rolling-element circulating system which is made up of a plurality of independent components, wherein the rolling-element retainers 11, 12, 13, the return path 14 and the return unit (including 15a and 15b) are independent components. The respective independent components are not integral with the slide block 4, there are too many independent components, and thus the assembly is complicated and time-consuming.
JP Patent 7-317762 discloses a rolling-element circulating system that is made by integral plastic ejection, in which, the slide block 13 is used as a part of the plastic ejection mold, and then the rolling-element supporting structure (the structure 17 which is made up of 30, 31 and 32), the return path 10 and the return unit (16 and 19) are integrally formed by plastic ejection. If the slide block is big size, then the size of the corresponding mold should be large. Furthermore, the plastic ejection process needs to be controlled precisely, and the difficulties are relatively increased. In this case, the dimension tolerance of the slide block must be controlled precisely before plastic ejection, so that the slide bock can be fully fitted into the mold. In addition, the supporting structure is difficult to be produced since it has long and thin sidewalls.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.